Note 16 - Supplemental Oil and Gas Disclosures (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Table Text Block]

	Years Ended December 31,
	(in thousands)
	2021			2022
Proved oil and gas properties	$	1,165,707		$	1,122,670
Unproved properties		-			-
Total		1,165,707			1,122,670
Accumulated depreciation, depletion, amortization and impairment		(1,074,144	)		(1,078,865	)
Net capitalized costs	$	91,563		$	43,805

Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure [Table Text Block]

	2021		2022
Development costs	$	1,145	$	1,509
Exploration costs		-		-
Property acquisition costs		-		-
	$	1,145	$	1,509

Results of Operations for Oil and Gas Producing Activities Disclosure [Table Text Block]

	2021			2022
Revenues	$	78,836		$	49,715
Production costs		(24,137	)		(14,562	)
Depreciation, depletion and amortization		(13,495	)		(4,720	)
Accretion of future site restoration		(330	)		(170	)
Results of operations from oil and gas producing activities (excluding corporate overhead and interest costs)	$	40,874		$	30,263
Depletion rate per barrel of oil equivalent	$	6.67		$	5.80

Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table Text Block]

	Total
							Oil
	Oil		NGL		Gas		Equivalents
	(MBbl)		(MBbl)		(MMcf)		(Mboe)
Proved Developed Reserves:
December 31, 2021		6,883		2,914		30,158		14,823
December 31, 2022		3,300		1,508		18,847		7,949
Proved Undeveloped Reserves:
December 31, 2021		-		-		-		-
December 31, 2022		-		-		-		-

Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure [Table Text Block]

	Years Ended December 31,
	(in thousands)
	2021			2022
Future cash inflows	$	485,982		$	431,728
Future production costs		(222,309	)		(192,611	)
Future development costs		(5,623	)		(4,728	)
Future income tax expense		-			-
Future net cash flows		258,050			234,389
Discount	$	(104,775	)	$	(100,511	)
Standardized Measure of discounted future net cash relating to proved reserves	$	153,275		$	133,878